SUMMARY OF PARENT GRANT AND PROPOSED SUPPLEMENT Parent Study: Through our parent U01, our National Drug Early Warning System (NDEWS) Coordinating Center aims to provide NIDA and the field with the most timely, salient, and valuable information on emerging substance use trends. By expanding data collection to include both former NDEWS sentinel sites as well as former Community Epidemiology Workgroup (CEWG) sites, and by incorporating novel surveillance methods to ensure early detection of signals of new psychoactive substances and known substances, our Early Warning Network extends geographic representation and provides a more complete picture of the size, direction, and depth of substance use patterns in all US Census regions. We will use novel surveillance methods to ensure early detection of signals indicating emerging drug trends and harmonize surveillance data across sentinel and CEWG sites. We will also conduct on-the-ground epidemiologic investigations on topics of immediate crisis or need in order to provide functional feedback to impacted communities towards optimizing current and future response, and we will disseminate results rapidly to the scientific community and the public alike. Proposed Supplement: The current COVID-19 crisis underscores a need for rapid assessments of the virus?s impact in substance-using populations throughout the NDEWS Early Warning Network, as people who use drugs appear to be at increased risk for COVID-19-related adverse outcomes and may find it more difficult to get care during the crisis. In addition, COVID-19 may alter one?s exposure to drug use, certain drugs, or might change patterns of drug use altogether. As an Early Warning System, NDEWS must be on the forefront of new trends in drug use, drug-related mortality, and drug treatment utilization, all of which may be either directly or indirectly impacted by COVID-19. Although in-person human subjects research has been halted, COVID-19 focused efforts that must begin now?with creative strategies that allow for immediate data to assess the impact of COVID-19 on substance use behaviors. In this proposed study, we will (Aim 1) collect rapid response data on substance use-related consequences of COVID-19 from novel key informants across the country in the urban, rural, and suburban areas represented by the 18 Early Warning Network sites, focused on decedents, family members of decedents, and the community at large. Key informants will include 1) funeral directors (n=200), 2) emergency medical service personnel (n=200), and 3) syringe exchange workers (n=75). We will (Aim 2) detect trends in patterns of drug-related mortality, health services utilization, including overdose reversals, and syringe exchange services by following up with key informants at 2, 3, 4, and 5 months post- baseline. We will then (Aim 3) rapidly disseminate the data to NIDA, through media outreach, and contribute to science through peer-reviewed publications. At a time when we cannot physically recruit or survey participants in person due to the COVID-19 crisis, we believe this is an extraordinary opportunity to collect rich data from key informants nationwide. Results will provide targets for new research strategies and prevention efforts.